I am trying through the array and use a Array.prototype.filter() method on every children array to find the elements whose key matches with the ones specified.

Then, I'am using Array.prototype.splice() to remove the results from the respective children array but the result is return undefined.

const inputArray = [
  "Oxygen-a3b8be32-c36e-a02e-37f4-a35239e0cedb",
  "633ac872e78fa7ebee03b8bf",
  "5e69dbd7-5fee-67a9-c73f-4656f9b90715",
  "d484558b-4717-b0b8-db07-68288afb4f6a",
  "63922aac4ff08f52d71fa891",
  "33a3182b-93a4-84b9-4c49-c955a8416197",
];

const originalArray = [{
    title: "Animals",
    key: "d484558b-4717-b0b8-db07-68288afb4f6a",
    children: [{
      title: "Color",
      key: "63922aac4ff08f52d71fa891",
      children: [{
          title: "Black",
          key: "Black-9e994ed2-823b-d1d6-4613-91d43f570fec",
        },
        {
          title: "White",
          key: "White-5d0b102a-2555-8f7c-d471-cc82a5bd9c01",
        },
      ],
    }, ],
  },
  {
    title: "Elements",
    key: "5e69dbd7-5fee-67a9-c73f-4656f9b90715",
    children: [{
      title: "Non metals",
      key: "633ac872e78fa7ebee03b8bf",
      children: [{
          title: "Carbon",
          key: "Carbon-e443daa4-def4-9830-796e-ee8c5a1f41d4",
        },
        {
          title: "Nitrogen",
          key: "Nitrogen-c2922569-0b2d-0e07-454d-d8411af701b7",
        },
        {
          title: "Oxygen",
          key: "Oxygen-a3b8be32-c36e-a02e-37f4-a35239e0cedb",
        },
      ],
    }, ],
  },
  {
    title: "Planets",
    key: "33a3182b-93a4-84b9-4c49-c955a8416197",
    children: [{
      title: "Composition",
      key: "63b3d5cd12c06ba7ce353f76",
      children: [{
          title: "Chthonian planet",
          key: "Chthonian planet-b3c593c1-d29e-5e14-1b11-2241e8ef2be6",
        },
        {
          title: "Carbon planet",
          key: "Carbon planet-07d67d62-afcf-fbcf-a8e8-75081cb44c2f",
        },
      ],
    }, ],
  },
];

console.log(
  "